Folding table and corresponding chopper folding device

ABSTRACT

A folding table, in particular for a folding device which is provided with a chopper folding device, includes a folding face which is suitable for receiving a flat product to be folded, and a folding aperture which extends in a conveying direction, the table extending along a table plane. The folding face includes guides which are capable of guiding at least one conveyor for conveying a flat product to be folded in the conveying direction.

BACKGROUND TO THE INVENTION

The present invention relates to a folding table, in particular for afolding device which is provided with a chopper folding device, of thetype comprising:

-   -   a folding face which is suitable for receiving a flat product to        be folded,    -   a folding aperture which extends in a conveying direction, the        table extending along a table plane.

Chopper folding devices are known which are suitable for folding a flatproduct, such as a sheet or a signature which has been printed in arotary offset press.

These chopper folding devices comprise a folding table, folding rollersand a folding blade. The folding blade is used in order to push the flatproducts through an aperture which is provided in the table in a gapwhich is formed by the rollers. The chopper folding device is providedwith belts for conveying the flat product in order to convey it onto thefolding table.

During the folding operation, the conveying belts are driven by theproduct to be folded in a transverse direction relative to the conveyingdirection thereof. Consequently, the belts overlap in a transversemanner and produce occurrences of jamming.

The machine time of known chopper folding devices is therefore low.

The object of the invention is to increase the machine time of a foldingdevice, in particular a chopper folding device.

SUMMARY OF THE INVENTION

To this end, the invention relates to a folding table, in particular fora folding device which is provided with a chopper folding device, of thetype indicated above, wherein the folding face comprises at least oneelement for conveying a flat product to be folded in the conveyingdirection, and guiding means, the guiding means being capable of guidingthe at least one element for conveying a flat product.

According to specific embodiments, the folding table comprises one ormore of the following features:

-   -   the table comprises a base body and the guiding means comprises        at least one guiding element which is arranged on the base body        and the base body and the at least one guiding element form the        folding face;    -   the at least one guiding element is a guiding rib;    -   the at least one guiding element is produced in one piece, in        particular integrally, with the base body; and    -   the folding face comprises an anti-friction coating, in        particular of chromium.

The invention also relates to a chopper folding device, of the typecomprising:

-   -   a folding table, and    -   at least one element for conveying a flat product to be folded,        in particular a conveying belt,

wherein the folding table is a folding table as defined above, and theat least one conveying element is guided by the at least one guidingelements.

According to specific embodiments, the chopper folding device comprisesone or more of the following features:

-   -   the at least one conveying element has a first height and the at        least one guiding element has a second height, these heights        being measured perpendicularly relative to the table plane, and        the second height is less than or equal to the first height;    -   the second height is strictly less than the first height, and in        particular the second height is between 0.5 and 0.8 times the        first height;    -   the at least one guiding element forms at least one guiding        channel in which a conveying element is arranged, in particular        a single conveying element;    -   the at least one guiding element is arranged between the folding        aperture and the associated conveying element.

Other aspects and advantages of the invention will be appreciated fromthe following description, given by way of example and with reference tothe appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a section through a chopper folding device according to theinvention;

FIG. 2 is a perspective view of the chopper folding device according tothe invention, the folding blade being omitted; and

FIG. 3 is a section, drawn to a larger scale, through a portion of thechopper folding device according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a cross-section through the chopper folding device accordingto the invention, generally designated 2.

The chopper folding device 2 comprises a folding table 4, a foldingblade 6 and two folding rollers 8, 10.

The folding blade 6 can be moved back and forth in a folding directionDP and is arranged at one side of the folding table 4. The two foldingrollers 8, 10 have parallel axes and together form a folding gap.

The chopper folding device 2 comprises lower conveying belts 12 andupper conveying belts 14. The conveying belts 12 and 14 are capable ofconveying flat products 16 to be folded, such as signatures or sheets,onto the folding table 4 in a conveying direction D and in a conveyingdirection S (see FIG. 2). To this end, the conveying belts 12 and 14extend parallel with respect to the conveying direction D and are drivenin the conveying direction S.

The folding table 4 comprises a folding face 18 which is directedtowards the folding blade 6 and a lower face 20 which is directedtowards the folding rollers 8, 10.

The folding table 4 delimits a folding aperture 22 through which theproducts 16 to be folded are pushed by the blade 6. The folding aperture22 extends parallel with the conveying direction D.

The folding table 4 is provided with means 24 for guiding the lowerconveying belts 12 in the conveying direction D. These guiding means 24are capable of acting counter to a deflection of the lower conveyingbelts 12 towards the folding aperture 22, therefore transverselyrelative to the direction D, when the product 16 to be folded is pushedby the folding blade 6 through the folding aperture 22.

To this end, the folding table 4 comprises a base body 26 and guidingribs 28 which extend in the conveying direction D.

The base body 26 is generally parellelepipedal. The ribs 28 are arrangedon the base body 26 and form the guiding means 24.

The ribs 28 and the base body 26 form the folding face 18.

Two adjacent guiding ribs 28 together form a guiding channel 30 (seeFIG. 3) in which either a lower conveying belt 12 or a plurality oflower conveying belts 12 extend(s). Furthermore, the conveying channel30 closest to the folding aperture 22 receives two lower conveying belts12. The two conveying belts 12 in the same conveying channel, at oneside and the other of the folding blade 6, are used to provide betterguiding and better retention during the operation for folding books,signatures, sheets, in particular narrow sheets (web of paper having asmall width).

Each guiding rib 28 is thus arranged between the associated lowerconveying belt 12 and the folding aperture 22 in order to be able toguide the belt 12 during the folding operation.

The lower conveying belts 12 have a first height H1, measuredperpendicularly relative to the table plane P, and each guiding rib 28has a second height H2 which is also measured perpendicularly relativeto the table plane P. Advantageously, the second height H2 is less than,identical to, or strictly less than the height H1 in order not to impedethe folding of the product 16 to be folded. In particular, the guidingrib 28 has a height H2 which is between 0.5 and 0.8 times the firstheight H1 and thus contributes to supporting the product 16 to be foldedduring the conveying operation.

Furthermore, the base body 26 and the ribs 28 are provided with ananti-friction coating 32 which is advantageously produced from chromium.This coating 32 promotes the sliding of the conveying belts 12 andproducts to be folded on the table 4.

It should be noted that, if the coating 32 is present, the second heightH2 is measured from the free surface of the coating 32 of the base body26 to the free surface of the coating 32 of the rib 28.

Also, the guiding ribs 28 are produced in one piece and in particularintegrally with the base body 26 which reduces the production costs ofthe folding device.

The base body 26 and the ribs 28 are produced, for example, from steelor aluminium.

The folding table according to the invention, using simple and economicmeans, reduces the risk of jamming for chopper folding devices and thusincreases the reliability of the folding device.

It should be noted that the conveying belts 12, 14 may be replaced withother conveying elements.

1-20. (canceled)
 21. A folding table comprising: a folding face suitablefor receiving a flat product to be folded; and a folding apertureextending in a conveying direction, the table defining and extendingalong a table plane, the folding face including at least one conveyorfor conveying a flat product to be folded in the conveying direction andguides, the guides being capable of guiding the at least one conveyor.22. The folding table according to claim 21 wherein the table includes abase body and the guides include at least one guiding element beingarranged on the base body, the base body and the at least one guidingelement forming the folding face.
 23. The folding table according toclaim 22 wherein the at least one guiding element is a guiding rib. 24.The folding table according to claim 23 wherein the table includes twoadjacent guiding ribs and at least one lower conveying belt, the twoadjacent guiding ribs together forming a guiding channel in which the atleast one lower conveying belt extends.
 25. The folding table accordingto claim 24 wherein the guiding channel closest to the folding aperturereceives two lower conveying belts.
 26. The folding table according toclaim 22 wherein the at least one guiding element is produced in onepiece.
 27. The folding table according to claim 26 wherein the at leastone guiding element is produced integrally, with the base body.
 28. Thefolding table according to claim 23 wherein the guiding rib is producedin one piece.
 29. The folding table according to claim 28 wherein theguiding rib is produced integrally, with the base body.
 30. The foldingtable according to claim 21 wherein the folding face includes ananti-friction coating.
 31. The folding table according to claim 31wherein the anti-friction coating includes chromium.
 32. The foldingtable according to claim 22 wherein the folding face includes ananti-friction coating.
 33. The folding table according to claim 32wherein the anti-friction coating includes chromium.
 34. A chopperfolding device comprising: a folding table in accordance with claim 21;and at least one conveyor for conveying a flat product to be folded; theat least one conveyor being guided by at least one guiding element. 35.The chopper folding device according to claim 34 wherein the at leastone conveyor is a conveying belt.
 36. The chopper folding deviceaccording to claim 34 wherein the at least one conveyor has a firstheight and the at least one guiding element has a second height, thefirst and second heights being measured perpendicularly relative to thetable plane, the second height being less than or equal to the firstheight.
 37. The chopper folding device according to claim 36 wherein thesecond height is strictly less than the first height.
 38. The chopperfolding device according to claim 37 wherein the second height isbetween 0.5 and 0.8 times the first height.
 39. The chopper foldingdevice according to claim 37 wherein the at least one guiding elementforms at least one guiding channel in which at least one conveyor isarranged.
 40. The chopper folding device according to claim 37 wherein asingle conveyor is arranged in the guiding channel.
 41. The chopperfolding device according to claim 39 wherein the at least one guidingelement is arranged between the folding aperture and the associatedconveyor.
 42. The folding table according to claim 21 wherein thefolding table is for a folding device including a chopper foldingdevice.